Thread-cutting device for sewing-machines.



No. 739,133. PATENTBD SEPT.15, 1903.

E. B. ALLEN.

THREAD CUTTING DEVICE FOR SEWING MACHINES.

APPLICATION FILED JAN. e, 1902.

N0 MODEL. 2 SHEETSSHEET 1.

m: Ncmus Frrzns co, s-uc'rourna, WASHINGTON n. c.

No. 739,133. PATENTED SBP1.15, 1903. E. B. ALLEN.

THREAD CUTTING DEVICE FOR SEWING MACHINES.

APPLICATION FILED JAN. 6, 1903.

H0 MODEL. 2 SHEETS-SHEET 2.

"cams PElERS co. vnpramua. wnsnmurou n c UNITED: STATES I Patented September 15, 1903. PATENT QFFICE.

EDWARD l3. ALLEN, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO THE SINGER JERSEY.

MANUFACTURING COMPANY, A CORPORATION OF NEW THREAD-CUTTING DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 739,133, dated September 15,1903.

Original application filed June 30, 1902, Serial No. 113,808. Divided and this application filed January 6, 1903. Serial N0.188,047. (No model.)

To all whom it may concern:

Be it known that I, EDWARD B. ALLEN, a citizen of the United States, residing at Eliza beth, in the county of Union and State of New Jersey, have invented certain new-and useful Improvements in Thread-Outtin g Devices for Sewing-Machines, of which the followingis a specification, reference being had therein to the accompanying drawings.

This invention has for its object to provide a thread cutting and'holding device for sewing-machines adapted to sever two or more separated threads close to the work when a stitching operation has been completed, as in stitching buttonholes or in forming groups of stitches by means of stitch-forming mechanisms comprising two or more needles, the severed ends of the threads running to the needles being held by thread-nipping elements forming parts of the cutting device. To this end the thread-cutter, which is preferably a shear-cuttin g and thread-nipping device, comprises a cutting-blade having a concaved cutting edge which in the cutting operation or as the shear-cutting device is closed serves to draw the separated threads toward each other or toward a common point or part of the thread-cutting blade, so that at the severing operation the severed ends of the threads will be properly engaged and will be held by the thread-nipping elements of the thread-cutter.

In the accompanying drawings, Figure 1 is a side elevation of a buttonhole-stitching machine with the present invention applied thereto; and Fig. 2 is a plan view of the lower part of the same machine, partly in horizontal section, on line 2 2, Fig. 1. Figs. 3 and 4 are detail plan and edge views, respectively, of the thread cutting and holding device; and

Fig. 5 is a detail view showing the two needlcs and parts of the needle-bars of the machine shown in Figs. 1 and2. Fig. 6 is an enlarged cross-sectionof the thread-cutter and thread-nipper, showing the same closed. The buttonhole cutting and stitching machine, in connection with whichthe present invention is illustrated, is the same as that fully shown and described in my application,

Serial No. 113,808, filed June 30, 1902, of which application the present case is a division. In this machine a thread-cutter-supporting arm or plate 130 is attached to one of the clamp arms or levers 104. Fixed to the cutter-supporting arm or plate 130 is a springplate 131, having a thread-nipping part 132, and pivotally mounted on the said arm or plate 130 is a cutter-lever 133, having a thread cutting and holding finger 134, provided with a concave inner edge, the lower stationary member or cutting edge of the shear threadcutter being formed on a finger 135 at the forward part of the plate 130. The finger 134is arranged to swing across the vertical path of the two needles 27 and 28(carried in the presentinstance by the needle-bars 25 and 26) or across the paths of the threads running from the work to the eyes of the said needles when the stitching and barring of a buttonhole has been completed and at which time the traveling needles are in the machine herein shown at the small or bar end of the buttonhole, the concave edge of said finger tending to draw the threads toward each other, so that the severed ends of said threads may both be properly held by the thread-nipping elements of the threadcutter. When the stitching operation for a buttonhole has been completed. and the machine has been stopped with both of the needles lifted, the cutter-lever 133 will be operated (in the present instance manually) to swing the cutting-finger 134 toward the cutting-finger 135 and beneath the thread-nipping part or finger 132. This operation of the lever 133 will sever both needle-threads close to the work and will clamp the ends of the threads running to the eyes of the needles between the upper surface of the finger 134 and the lower surface of the thread-nipping finger 132. During the stitching of the next succeeding buttonhole after the needles have traveled away from the finger 134 toward the eye portion of the buttonhole the lever 133 will be operated (in the present instance again manually) to swing the said finger back to its first position to open the shears for the next thread-cutting operation.

The machine herein shown is provided with an automatic clamp-opening device comprising a sliding rod 137, mounted for endwise movement in ears 136, supported by the arm of the machine and having an attached collar 140 pressed against by a coil-spring 141 in such a manner as to move the said sliding rod forward after the clamp-opening operation, as fully described in my said application, Serial No. 113,808. The rod 137 is provided with a notch 144, engaged when the said rod is drawn rearward by the hooked end 142 of a spring-pressed latch-lever 143, serving to hold the rod rearward against the stress of the coil-spring 141 until the said latch-lever is released. In the present instance I provide means for manually releasing the said latch-lever simultaneously with the threadcutting operation by connecting the threadcutting lever 133 with the said latch-lever by a rod 148, sliding freely through a hole in the said latch-lever and provided with a collar or projection 149, which will engage the said latch-lever and lift its hooked nd out of the notch 144 of the sliding rod 137 when the thread-cutter is closed to sever the thread. I do not, however, herein claim this feature of releasing the clamp-opening device from the thread-cutting device, as said feature is claimed in my application above referred to.

The present invention is not to be understood as being limited to a manually-operated thread-cutting and thread-nipping device or to the details of construction herein shown or to the use of the invention with a buttonhole-stitching machine, as it is obvious that the details of the invention may be varied and that the invention may be employed in connection with embroidery or other sewing machines having two or more threads to be simultaneously severed and which in the thread-severing operation will be drawn toward each other by the concave member of the thread-cutting device.

Having thus described my invention, I claim and desire to secure by Letters Patent 1. In a sewing-machine, the combination with a plurality of separated thread-carrying members, of a thread-cutting and threadnipping device mounted adjacent to said thread-carrying members and comprising a movable cutting-blade having a concave part serving to draw the separated threads of said members toward each other at the threadsevering operation, so that the severed ends of the said threads will be properly held by the thread-nipping elements of the said device.

2. A shear thread-cutting and thread-nipping device, consisting of the combination with the lower stationary cutting-blade 135, of the cutting-lever 133 pivotally mounted with reference to the said stationary blade and provided with the finger 134 having a concaved cutting edge of such extent as to be adapted to embrace several separated threads and draw them toward each other for threadcutting and thread-nipping operation, and a spring-mounted thread-nipping part 132 between which and the stationary blade 135 the said concaved finger 134 is arranged to move, so as to sever the needle-threads the ends of which will be held between the said finger 134 and the thread-nipping part 132 while the cutting device remains closed.

3. In a buttonhole cutting and stitching machine, the combination with a work-clamp and a feeding mechanism for spacing the stitches, of a stitch-forming mechanism comprising a plurality of separated needles, and a thread-cutting and thread-nipping device mounted adjacent to the vertical path of said needles and comprising a cutting-blade having a concave inner or cutting edge of such extent as to embrace the several separated threads and draw them toward each other at the severing operation, so that the severed ends of said threads can both be properly held by the thread-nipping elements of said cutter.

In testimony whereof I aflix my signature in presence of two witnesses.

EDWARD B. ALLEN.

Witnesses:

HENRY J. MILLER, HENRY A. KORNEMANN. 

